PC maker Dell (NASDAQ:DELL) is said by Bloomberg to be conducting discussions over the possible acquisition of systems management software supplier Quest Software (NASDAQ:QSFT), as the former continues its shift to higher-end business customers. Shares of Quest moved significantly higher on the news, and currently stand far above the March offer of $23 from private equity firm Insight; the former’s market cap is approximately 10 percent of that of would-be purchaser Dell. Further, it’s possible that interest in Quest’s competitor BMC Software (NASDAQ:BMC) could perk up if Dell does go through with the acquisition.

Lehman Brothers (LEHMQ.PK) says that it will pay $1.58 billion for the remaining 26.5 percent investment in apartment major Archstone, from Bank of America (NYSE:BAC) and Barclays (NYSE:BCS). As a part of the deal, Sam Zell’s Equity Residential (NYSE:EQR) will get a break-up fee of $150 million from Lehman and the banks, since it also tried to acquire the stake in Archstone.

The European Union gives its approval to Eastman Chemical (NYSE:EMN) for its acquisition of Solutia (NYSE:SOA) for a price of $3.4 billion. Eastman forecasts that the transaction will be immediately accretive, and that the combined group should be saving approximately $100 million in annual costs by the end of 2013.

Shares of satellite imagery companies DigitalGlobe (NYSE:DGI) and GeoEye (NASDAQ:GEOY) move up in tandem on rumors of a higher bid for the former, by the latter. DGI rejected a $17 offer from GeoEye earlier in May.